Simplify passing of AccessorInfo to interceptors:

src/ia32/stub-cache-ia32.cc

Index: src/ia32/stub-cache-ia32.cc
diff --git a/src/ia32/stub-cache-ia32.cc b/src/ia32/stub-cache-ia32.cc
index e554a31c7166b3bd8055ac8253c48f213ae6a9d9..5e61ffcfa12457c2848b5fc02d0be20fa38b9831 100644
--- a/src/ia32/stub-cache-ia32.cc
+++ b/src/ia32/stub-cache-ia32.cc
@@ -276,14 +276,15 @@ static void PushInterceptorArguments(MacroAssembler* masm,
                                      Register holder,
                                      Register name,
                                      JSObject* holder_obj) {
-  __ push(receiver);
-  __ push(holder);
   __ push(name);
   InterceptorInfo* interceptor = holder_obj->GetNamedInterceptor();
   ASSERT(!Heap::InNewSpace(interceptor));
-  __ mov(receiver, Immediate(Handle<Object>(interceptor)));
+  Register scratch = name;
+  __ mov(scratch, Immediate(Handle<Object>(interceptor)));
+  __ push(scratch);
   __ push(receiver);
-  __ push(FieldOperand(receiver, InterceptorInfo::kDataOffset));
+  __ push(holder);
+  __ push(FieldOperand(scratch, InterceptorInfo::kDataOffset));
 }
 
 
@@ -1045,17 +1046,16 @@ bool StubCompiler::GenerateLoadCallback(JSObject* object,
   __ push(receiver);  // receiver
   __ push(reg);  // holder
   __ mov(other, Immediate(callback_handle));
-  __ push(other);
   __ push(FieldOperand(other, AccessorInfo::kDataOffset));  // data
   __ push(name_reg);  // name
   // Save a pointer to where we pushed the arguments pointer.
-  // This will be passed as the const Arguments& to the C++ callback.
+  // This will be passed as the const AccessorInfo& to the C++ callback.
   __ mov(eax, esp);
-  __ add(Operand(eax), Immediate(5 * kPointerSize));
+  __ add(Operand(eax), Immediate(4 * kPointerSize));

[antonm, 2010/03/25 14:40:53]

could we use some named constant for this 4?

[Vitaly Repeshko, 2010/03/25 17:08:56]

This is a local thing: it's the depth of the arguments pointer as described in
the comment.

   __ mov(ebx, esp);
 
   // Do call through the api.
-  ASSERT_EQ(6, ApiGetterEntryStub::kStackSpace);
+  ASSERT_EQ(5, ApiGetterEntryStub::kStackSpace);

[antonm, 2010/03/25 14:40:53]

do you I understand it right, this is not ported to other platforms?  do you
know if we have corresponding bugs filed?

[Vitaly Repeshko, 2010/03/25 17:08:56]

Right, this is not ported to other platforms and I couldn't find a relevant bug.
Filed http://code.google.com/p/v8/issues/detail?id=663

   Address getter_address = v8::ToCData<Address>(callback->getter());
   ApiFunction fun(getter_address);
   ApiGetterEntryStub stub(callback_handle, &fun);